The present application relates to back-end-of-the-line (BEOL) technology. More particularly, the present application relates to an interconnect structure including a liner located between an electrically conductive structure and an interconnect dielectric material layer that is composed of a phase change material that is insulating at a first temperature, and becomes conductive at a second temperature that is higher than the first temperature.
Generally, BEOL interconnect devices include a plurality of circuits which form an integrated circuit fabricated on an interconnect substrate. A complex network of signal paths will normally be routed to connect the circuit elements distributed on the surface of the substrate. Efficient routing of these signals across the device requires formation of multilevel or multilayered schemes, such as, for example, single or dual damascene wiring, i.e., interconnect, structures.
Within typical interconnect structures, electrically conductive metal vias run perpendicular to the interconnect substrate and electrically conductive metal lines run parallel to the interconnect substrate. Typically, the electrically conductive metal vias are present beneath the electrically conductive metal lines and both features are embedded within an interconnect dielectric material layer.
In conventional interconnect structures, copper or a copper containing alloy has been used as the material of the electrically conductive metal or metal alloy of the electrically conductive structure that is embedded in an interconnect dielectric material. Conventional interconnect structures may also include various liners such as, for example, metallic liners, and/or diffusion barrier liners. Conventional liners are composed of materials (either conductive or insulating) that do not undergo any phase change upon heating of the interconnect structure. Thus, the conventional liners are not used to provide a redundancy electrical path when the temperature of the interconnect structure increases. Also, conventional liners cannot used to provide a local redundancy electrical path when an electromigration event occurs. There is thus a need for providing a liner material for an interconnect structure that can provide either a redundancy electrical path or a localized redundancy electrical path.